Communication apparatus, control method of the same, and non-transitory computer-readable storage medium

ABSTRACT

A communication apparatus receives a first acquisition request, which is a request for acquiring apparatus information relating to another communication apparatus that exists in a NAN (Neighbor Awareness Networking) cluster, from a first other communication apparatus, transmits, in a case where the first acquisition request is received, a second acquisition request that corresponds to the first acquisition request to the cluster, and awaits reception of signals from a plurality of other communication apparatuses in response to the transmitted second acquisition request, for a predetermined period. In addition, a signal is transmitted which includes pieces of apparatus information of the plurality of other communication apparatuses that are included in the signals received from the plurality of other communication apparatuses collectively to the first other communication apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of International Patent ApplicationNo. PCT/JP2016/083302, filed Nov. 10, 2016, which claims the benefit ofJapanese Patent Application No. 2016-008290, filed Jan. 19, 2016, bothof which are hereby incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a communication apparatus, a controlmethod of the same, and a non-transitory computer-readable storagemedium.

Background Art

Wireless local area network (LAN) systems represented by the IEEE802.11are widely used. In a wireless LAN, the network is controlled by a basestation called an access point (AP). The wireless network is constitutedby this AP and a station (STA) that exists in a coverage of radio wavesof the AP and is wirelessly connected to the AP. Recently, products andspecification standards have been proposed that cover not only suchsimple conventional wireless network configurations constituted by an APand a STA but also various wireless LAN network morphologies.

Neighbor Awareness Networking (NAN) has been defined by the Wi-FiAlliance as a communication standard for discovering communicationapparatuses or services provided by the communication apparatuses withreduced electric power. According to the NAN, periods in whichcommunication apparatuses (hereinafter, referred to as “NAN devices”)constituting the NAN exchange information are synchronized. This canshorten a period in which the wireless communication function of the NANdevices is enabled, and save electric power.

In the NAN, periodic time periods for synchronization are referred to as“Discovery Window (DW)”. Furthermore, the network constituted by a groupof NAN devices that share predetermined synchronization periods isreferred to as a NAN cluster.

A NAN device can take one of the following roles within the NAN cluster:Master; Non-Master Sync; and Non-Master Non-Sync. The NAN device thatcan take the role of Master transmit, in a DW period, a Sync Beacon,which is a signal for enabling synchronization of NAN devices in thesame NAN cluster. Once the synchronization has been established, the NANdevices within the NAN cluster transmit and receive a Subscribe message,which is a signal for searching for a service, and a Publish message,which is a signal for giving a notification indicating that the serviceis provided, to and from each other in a DW period. Furthermore, the NANdevices can transmit and receive a Follow-up message for exchangingadditional information related to the service in a DW period. The framestructures of the messages such as Publish, Subscribe, and Follow-upmessages are defined according to the NAN standard, and are referred toas Service Discovery Frames (SDFs). The SDFs include Service ID, whichis an identifier for specifying a target service. As a result of NANdevices transmitting and receiving SDFs to and from each other, servicescan be discovered and detected.

CITATION LIST Patent Literature

PTL1: US-2014-302787

As described above, NAN devices can discover and detect a service withina NAN cluster. However, a NAN device cannot acquire, form another devicelocated within the NAN cluster but outside of the coverage of radiowaves of that NAN device, NAN device information (for example,information (such as “Master Rank” or “Random Factor”) that serves as abasis for deciding which one of the roles of Master, Non-Master Sync,and Non-Master Non-Sync a NAN device takes). Under such a situation, theNAN device cannot also recognize how many NAN devices exist for eachrole in the NAN cluster, and how many hopes forward in the cluster theyexist.

The following method is conceivable as a method for a NAN device toacquire information relating to how many other NAN devices exist in theNAN cluster and which role they take. First, the NAN device broadcasts,to its neighbor, a message for requesting NAN device information. A NANdevice that could receive it responds to the request. Furthermore, inorder for the NAN device to acquire NAN device information from anotherNAN device outside of the coverage of radio waves of that NAN device, afirst other NAN device that has received the request forwards therequest to a second other NAN device (that is, the NAN device outside ofthe coverage of radio waves). Then, the second other NAN device that hasreceived the forwarded message gives a response to the forwarded messagewith a message including its NAN device information, and the first otherNAN device forwards the response to the original NAN device that desiresto acquire information. By repeating such processing, the NAN device canacquire NAN device information of another NAN device that exists in theNAN cluster.

However, the above-described method has the following problem. That is,due to repetition of forwarding processing, the amounts of messages inthe entire NAN cluster increase. According to the NAN standard, a periodin which all NAN devices can perform reception is defined as “DW(Discovery Window) period”, which is a time period of 16 TUs for everycycle of 512 TUs (1 TU=1024 μsec). Accordingly, if a NAN devicetransmits and receives many messages in this short time period of 16TUs, the NAN device is unlikely to transmit a message for discoveringand searching for a service. Therefore, such a problem may occur that aservice cannot be discovered, or it takes a very long time until aservice is discovered.

The present invention is made in view of the above-described problems,and it is an object thereof to provide a technique for reducing radioband occupancy when information relating to another communicationapparatus that exists in a cluster is acquired.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided acommunication apparatus comprising: one or more processors; and one ormore memories including instructions that, when executed by theprocessor (s), cause the apparatus to: receive a first acquisitionrequest, which is a request for acquiring apparatus information relatingto another communication apparatus that exists in a NAN (NeighborAwareness Networking) cluster, from a first other communicationapparatus; transmit, in a case where the first acquisition requestsignal is received, a second acquisition request signal that correspondsto the first acquisition request to the cluster; await reception ofsignals from a plurality of other communication apparatuses in responseto the transmitted second acquisition request signal, for apredetermined period; and transmit pieces of apparatus information ofthe plurality of other communication apparatuses that are included inthe signals received from the plurality of other communicationapparatuses collectively to the first other communication apparatus.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included in the description, constitutepart thereof, show embodiments of the present invention, and are used,together with the descriptions thereof, to explain the concept of thepresent invention.

FIG. 1 is a diagram illustrating a configuration of a wireless networkaccording to an embodiment.

FIG. 2 is a diagram illustrating a functional configuration of a NANdevice according to an embodiment.

FIG. 3 is a diagram illustrating a hardware configuration of the NANdevice according to an embodiment.

FIG. 4 is a diagram illustrating a sequence according to a firstembodiment.

FIG. 5 is a flowchart of reception waiting processing according to thefirst embodiment.

FIG. 6 is a diagram illustrating a configuration of an extendedSubscribe message of an embodiment.

FIG. 7 is a diagram illustrating a configuration of extended Publishmessage of an embodiment.

FIG. 8 is a diagram illustrating a configuration of an extendedFollow-up message of an embodiment.

FIG. 9 is a diagram illustrating a sequence according to a secondembodiment.

FIG. 10 is a flowchart of reception waiting processing according to thesecond embodiment.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, the present invention will be described based onembodiments thereof with reference to the accompanying drawings. Notethat the configurations shown in the following embodiments are merelyexamples, and the present invention is not limited to the shownconfigurations.

First Embodiment

FIG. 1 shows an exemplary network configuration according to the presentembodiment. The following will describe an example in which a wirelessLAN system conforming to the Neighbor Awareness Networking (NAN)standard is used.

A NAN device 102 is a wireless communication apparatus that is compliantwith the NAN standard, and is capable of performing processing that willbe described in detail later. Note that the NAN device 102 may be adevice of any type as long as it can participate in the NAN and cancommunicate with another NAN device in a NAN cluster. NAN devices 101,and 103 to 106 are wireless communication apparatuses that are compliantwith the NAN standard. Note that the NAN devices 101, and 103 to 106also have the same configuration as the configuration of the NAN device102, which will be described in detail later, and are capable ofperforming the same processing as that of the NAN device 102. The NANdevices 101 to 106 can discover and provide, based on the NAN standard,neighbor communication apparatuses or services provided by them. In FIG.1, the NAN devices 101 to 106 participate in a NAN cluster 107. The NANdevices 101, 105, and 106 participate in the NAN cluster 107 as“Non-Master Non-Sync”, and the NAN devices 102, 103, and 104 participatein the NAN cluster 107 as “Master”. In the present embodiment, the NANdevice 101 operates to acquire NAN device information of another NANdevice participating in the NAN cluster 107.

It is assumed that only the NAN device 102 exists in the coverage ofradio waves of the NAN device 101, and the NAN device 101 cannotcommunicate with the NAN devices 103 to 106 because they aregeographically far from this NAN device. Similarly, it is assumed thatonly the NAN devices 101, 103, and 104 exist in the coverage of radiowaves of the NAN device 102, and the NAN device 102 cannot communicatewith the NAN devices 105 and 106. It is assumed that only the NANdevices 102 and 105 exist in the coverage of radio waves of the NANdevice 103, and the NAN device 103 cannot communicate with the NANdevices 101, 104, and 106. It is assumed that only the NAN devices 102and 106 exist in the coverage of radio waves of the NAN device 104, andthe NAN device 104 cannot communicate with the NAN devices 101, 103, and105. Furthermore, it is assumed that the NAN device 105 and the NANdevice 106 are located at positions at which they cannot communicatewith each other.

The NAN cluster 107 is a network in which the NAN devices 101 to 106 areparticipating. In the present embodiment, the NAN devices 101 to 106participating in the NAN cluster 107 constitute a network using 6 ch. Inthe network of the NAN cluster 107, a Discovery Window (DW) is 16 TimeUnits (TUs), and there is an interval of 512 TUs between the start ofthe DW and the start of the next DW. Note that wireless channels and aDW configuration of the NAN are not limited to these. Each NAN devicetransmits and receives a frame to and from each other only during the DWperiod, and does not transmit and receive a frame during a period otherthan the DW period, thereby reducing a power consumption.

FIG. 2 is a diagram illustrating a functional configuration of the NANdevice 102. A wireless LAN control unit 201 performs control fortransmitting and receiving a wireless signal to and from anotherwireless LAN device. Also, the wireless LAN control unit 201 performswireless LAN control in compliance with IEEE802.11. A NAN control unit202 performs control in compliance with the NAN standard. For example,once the synchronization with other NAN devices in the NAN cluster 107has been established, the NAN control unit 202 transmits and receivesthe above-described SDF to discover and detect a service. A waiting timedetermination unit 203 controls the NAN control unit 202 to determinethe waiting time for receiving a message that includes NAN deviceinformation transmitted from another NAN device. The details of theprocessing that is executed by the waiting time determination unit 203will be described later with reference to FIGS. 4 and 5.

An application control unit 204 performs control for executing adiscovered service. For example, if the NAN device 102 has discovered aprinting service, then the application control unit 204 performs controlfor executing an application for requesting a print job. Alternatively,if the NAN device 102 has discovered a photo-sharing service, then theapplication control unit 204 performs control for executing anapplication for exchanging photographic data. The NAN device 102 mayalso include a plurality of application control units 204 to execute aplurality of services. An operation control unit 205 manages operationsmade on the NAN device 102 by a user via an input unit 304 (FIG. 3) andtransfers required signals to the other control units 201 to 204.

FIG. 3 shows a hardware configuration of the NAN device 102. A storageunit 301 is made of both or one of a ROM (Read Only Memory) and a RAM(Random Access Memory) and stores various types of programs forexecuting various operations that will be described later, andinformation such as communication parameters for wireless communication.Note that besides such memories as the ROM, the RAM and the like, astorage medium such as a flexible disk, a hard disk, an optical disk, amagnetic optical disc, a CD-ROM, a CD-R, an electromagnetic tape, anonvolatile memory card, or a DVD may be used as the storage unit 301.

A control unit 302 is constituted by a CPU (Central Processing Unit) oran MPU (Micro Processing Unit), and controls the entire NAN device 101by executing a program stored in the storage unit 301. Note that thecontrol unit 302 may also control the entire NAN device 101 incooperation with a program stored in the storage unit 301 and an OS(Operating System). Furthermore, the control unit 302 controls afunctional unit 303 to execute predetermined processing such as imagecapture, printing, or projection.

The functional unit 303 is a piece of hardware for causing the NANdevice 101 to execute predetermined processing. For example, if the NANdevice 101 is a camera, the functional unit 303 is an image capturingunit, and performs image capturing processing. Furthermore, for example,if the NAN device 101 is a printer, the functional unit 303 is aprinting unit, and performs printing processing. Furthermore, forexample, if the NAN device 101 is a projector, the functional unit 303is a projection unit, and performs projection processing. Data that isprocessed by the functional unit 303 may be data stored in the storageunit 301, or data communicated with another NAN device via alater-described communication unit 306.

The input unit 304 accepts various types of operations from the user. Anoutput unit 305 performs various types of output for the user. Here,output by the output unit 305 includes at least one of on-screendisplay, audio output using a speaker, vibration output, and the like.Note that both the input unit 304 and the output unit 305 may also berealized by a single module such as a touch panel.

The communication unit 306 controls wireless communication conforming tothe IEEE802.11 series, and controls IP (Internet Protocol)communication. Furthermore, the communication unit 306 controls anantenna 307 to transmit and receive a wireless signal for wirelesscommunication. The NAN device 101 communicates content such as imagedata, document data, and video data with another NAN device via thecommunication unit 306.

The following will describe, with reference to a sequence diagram ofFIG. 4, an exemplary flow of a series of processes performed when theNAN device 101 acquires NAN device information of the NAN devices 102 to106 within the NAN cluster 107, according to the present embodiment.Note that numbers in parentheses denote the NAN device information ofcorresponding one of the NAN devices 102 to 106.

In the present example, it is assumed that the NAN device 101 broadcastsa request (extended Subscribe message, details of which will bedescribed later with reference to FIG. 6) for acquiring NAN deviceinformation (apparatus information) within the NAN cluster 107 inaccordance with a user operation. The NAN device 102 that has receivedthis request responds to the request, and forwards the request bybroadcasting it. Accordingly, NAN devices outside of the coverage ofradio waves of the NAN device 101 can receive that request.

Note that in the present embodiment, it is assumed that the NAN devicesthat take the roles of Master and Non-Master Sync can forward a requestof a NAN device. This is because the NAN devices taking these rolestransmit a Sync Beacon on a regular basis, and the NAN device that takesthe role of Non-Master Non-Sync can participate in the NAN cluster if itcan receive the Sync Beacon. In other words, as a result of the NANdevices that take the role of Non-Master Non-Sync not performingforwarding processing, it is possible to prevent unnecessary bandoccupancy. In the present embodiment, as shown in FIG. 1, in the NANcluster 107, the NAN devices 102, 103, and 104 take the role of Master,and the NAN devices 101, 105, and 106 take the role of Non-MasterNon-Sync. Accordingly, the NAN devices 102, 103, and 104 can forward arequest from a NAN device.

In step S401, first, a user of the NAN device 101 starts processing foracquiring NAN device information of a NAN device within the NAN cluster107 via the input unit 304 of the NAN device 101. Even after havingstarted the processing for acquiring NAN device information, the NANdevice 101 does not transmit a Subscribe message for requesting NANdevice information acquisition until a DW period.

In a DW period 420, the NAN device 101 transmits a Subscribe message bybroadcasting it (step S402). In DW periods, the NAN devices 102, 103,and 104 taking the role of Master transmit a Sync Beacon, but heredescription of transmission of a Sync Beacon is omitted. A Subscribemessage of the present embodiment is an extended Subscribe message forrequesting NAN device information that is obtained by extending aSubscribe message defined according to the NAN standard.

FIG. 6 shows an extended Subscribe message configuration 600 accordingto the present embodiment. The message configuration 600 of FIG. 6 isobtained by extending a Publish message defined according to the NANstandard, and in “Service ID”, a value representing “Collect”, whichindicates that it is a Subscribe message relating to a service ofrequesting (that is, collecting) NAN device information, is stored.Furthermore, in “Service Info”, various types of information forrequesting NAN device information are stored. In “Originator MACAddress”, a MAC address of an originator that has requested NAN deviceinformation is stored. That is, in step S402 (and the subsequent stepsS404, S408, and S409), the MAC address of the NAN device 101 is storedin “Originator MAC Address”.

To “Collect ID” that follows “Originator MAC Address”, when apparatusinformation has been requested multiple times, IDs for identifying therespective apparatus information requests are assigned. For example,when the NAN device 101 has requested NAN device information multipletimes, different values are assigned to “Collect ID” of the respectiveextended Subscribe messages. Accordingly, the NAN device that hasreceived an extended Subscribe message can detect whether or not thereceived extended Subscribe message is redundant. If the extendedSubscribe message of the same Collect ID is detected as having beenreceived, the NAN device that has received the extended Subscribemessage recognizes that the received extended Subscribe message isredundant and does not respond and forward it. On the other hand, ifhaving been received an extended Subscribe message with a Collect IDthat has not been received before, the NAN device forward the extendedSubscribe message without changing the value of the Collect ID.

In “Hop Count” that follows “Collect ID”, the value indicating thenumber of times that the extended Subscribe message has been forwardedbefore is stored. Accordingly, 0 is stored in “Hop Count” of theextended Subscribe message transmitted by the NAN device 101. Also, theNAN device 102 that has received the extended Subscribe message from theNAN device 101 sets the value of “Hop Count” to 1 and forwards theextended Subscribe message.

To “Hop Count Limit” that follows “Hop Count”, the number of times thatthe extended Subscribe message is allowed to be forwarded is assigned.For example, if an extended Subscribe message in which 0 is assigned toits Hop Count Limit is transmitted by the NAN device 101, the NAN device102 that has received it is not allowed to forward the extendedSubscribe message. Furthermore, if an extended Subscribe message inwhich 1 is assigned to its Hop Count Limit is transmitted by the NANdevice 101, the NAN device 102 that has received it assigns 1 to “HopCount” and forwards it. Then, the NAN device that has received theforwarded extended Subscribe message is not allowed to extend andforward the Subscribe message, since “Hop Count Limit” has reached itsupper limit.

By performing assignment to “Hop Count” and “Hop Count Limit” in thisway, the NAN device 101 can assign the range in which an extendedSubscribe message can be transmitted. In other words, the NAN device 101can assign the number of hops of NAN devices for NAN device informationacquisition targets within the NAN cluster 107.

The description will return to FIG. 4. In the extended Subscribe messagein step S402, it is assumed that 0 is stored in its Hop Count, 2 isstored in its Hop Count Limit. It is also assumed that a unique valuethat has not assigned before is assigned to its Collect ID. The extendedSubscribe message transmitted from the NAN device 101 is received by theNAN device 102 located in the coverage of radio waves of the NAN device101.

Upon receiving the extended Subscribe message, the NAN device 102responds, in step S403, with an extended Publish message in which theNAN device information of the NAN device 102 is stored. The extendedPublish message according to the present embodiment is an extendedPublish message obtained by extending a Publish message definedaccording to the NAN standard.

FIG. 7 shows an extend Publish message configuration 700 according tothe present embodiment. The message configuration 700 of FIG. 7 isobtained by extending a Publish message defined according to the NANstandard, and in “Service ID”, a value representing “Collect”, whichindicates that it is a Publish message relating to a service ofrequesting (that is, collecting) NAN device information, is stored.Furthermore, in “Service Info”, various types of information forresponding with NAN device information are stored. In “Originator MACAddress”, a MAC address of an originator that has requested NAN deviceinformation is stored. That is, in the present embodiment, the MACaddress of the NAN device 101 is stored in “Originator MAC Address”. To“Collect ID”, the Collect ID included in the received extended Subscribemessage is assigned. Accordingly, the NAN device that has received theforwarded extended Publish message can identify the NAN deviceinformation request to which the response is made.

In “NAN device information” that follows “Collect ID”, various types ofinformation relating to the NAN device are stored. The first piece ofinformation included in “NAN device information” is a MAC address foridentifying the NAN device to which the NAN device information relates.In step S403, the MAC address of the NAN device 102 is stored in “NANdevice information”. In “Device Name” that follows “MAC address”, acharacter string is stored for identifying which NAN device it is. Instep S403, the character string “NAN Device 102” is stored.

To “Cluster ID” that follows “Device Name”, a Cluster ID that is definedaccording to the NAN standard is assigned to identify the cluster towhich the device belongs. In the present embodiment, the Cluster ID thatcorresponds to the NAN cluster 107 is assigned. In “Role”, a role of theNAN device is stored. That is, information for identifying which role ofMaster, Non-Master Sync, or Non-Master Non-Sync the device participatingin the NAN cluster takes is stored in “Role”. In “Hop Count”, the valueindicating how many hops the NAN device is away from the originator NANdevice is stored. In step S403, the response is made by the NAN device102, which is not hopped from the originator NAN device 101 that hasrequested the NAN device information, and thus 0 is stored in “HopCount”. That is, the NAN device 102 sets the Hop Count assigned in thereceived extended Subscribe message in the extended Publish message andresponds with it. “Master Preference” and “Random Factor” that follow“Hop Count” include information that indicates the likelihood that thedevice takes the role of Master or Non-Master Sync defined according tothe NAN standard. A NAN device that has received an extended Publishmessage including this information can recognize the likelihood that theNAN device from which the message has been transmitted takes the role ofMaster.

To “Master MAC Address” and “Anchor Master MAC Address”, MAC addressesof a Master NAN device and an Anchor Master NAN device that havetransmitted a Sync Beacon for synchronization of the NAN devices withinthe NAN cluster are assigned. Note that “Anchor Master” is a NAN devicethat serves as a basis for determining the time reference within the NANcluster. The MAC address of the NAN device 102 is stored in “Master MACAddress” and “Anchor Master MAC Address” since, in step S403, the NANdevice 102 takes the role of Master and the role of Anchor Master.

“Anchor Master Preference” and “Anchor Master Random Factor” that follow“Anchor Master MAC Address” include information indicating thelikelihood that the NAN device taking the role of Anchor Master transitsto the NAN device taking the role of Master or the role of Non-MasterSync. A NAN device that has received an extended Publish messageincluding this information can recognize whether or not the NAN devicetaking the role of Anchor Master can stably continue to be an AnchorMaster within the NAN cluster, that is, whether or not the NAN clusteris stable. In “Hop Count to Anchor Master” that follows them, the numberof hops from the NAN device to the NAN device taking the role of AnchorMaster is stored. An extended Publish message is a message to bereturned as a response to the NAN device that has transmitted an inquiryor the NAN device that has forwarded the inquiry, and thus istransmitted through unicast.

The description will return to FIG. 4. Since the extended Subscribemessage received in step S402 has Hop Count=0 and Hop Count Limit=2, theNAN device 102 forwards the extended Subscribe message to furtheracquire information also from another NAN device (step S404). At thistime, the same values as in step S402 are assigned to “Originator MACAddress”, “Collect ID”, and “Hop Count Limit” of the extended Subscribemessage. On the other hand, the Hop Count is incremented to 1 becausethe Subscribe message in step S404 is a forwarded message of theSubscribe message of step S402.

In step S404, the NAN device 101 that has received the Subscribe messagecan determine that the Subscribe message is a forwarded message of theextended Subscribe message transmitted by the NAN device 101 itself instep S402, based on the Originator MAC Address and the Collect ID, andthus the NAN device 101 does not respond to the reception. On the otherhand, the NAN devices 103 and 104 each transmit an extended Publishmessage as a response (steps S405 and S406), because they have receivedthe extended Subscribe message that includes a Collect ID that has notreceived before. At this time, the NAN device information of the NANdevice 103 is stored in the extended Publish message that is transmittedin step S405, and the NAN device information of the NAN device 104 isstored in the extended Publish message that is transmitted in step S406.Furthermore, 1 is assigned to “Hop Count” as in the Subscribe message ofstep S404. Accordingly, the NAN device 101 can recognize that the NANdevices 103 and 104 are NAN devices that are located at one hop forwardfrom the NAN device 101 via the NAN device 102.

The NAN device 102 that has forwarded the extended Subscribe message instep S404 notifies, upon receiving an extended Publish message in whichNAN device information of another NAN device is stored, the NAN device101 of the NAN device information. However, the band usage isinefficient if only one piece of NAN device information is transmittedfor each message. Accordingly, the NAN device 102 does not immediatelytransmit the information of the NAN device 103 that was received in stepS405 to the NAN device 101, and waits for possible reception of messagesincluding NAN device information from a larger number of NAN devices, inaccordance with the flowchart shown in FIG. 5. Then, the NAN device 102transmits the NAN device information of the NAN device 103 that wasreceived in step S405 to the NAN device 101.

FIG. 5 shows a flowchart of processing in which, when having received anextended Publish message or a later-described extended Follow-upmessage, the NAN device 102 waits for receiving another message, andtransmits NAN device information included in the received message as anextended Follow-up message. Note that the present processing may also beperformed by another NAN device existing in the NAN cluster 107.

When having received an extended Publish message, the NAN device 102does not transmit the extended Follow-up message during the DW period inwhich this extended Publish message has been received. Then, the NANdevice 102 waits for receiving an extended Publish message or anextended Follow-up message from another NAN device until the DW periodis complete (step S501).

After the DW period is complete, the NAN device 102 determines whetheror not an extended Publish message or an extended Follow-up message hasbeen received during the latter half TU of the DW period, namely, thelast period of 2 TUs in the present embodiment (step S502). If anextended Publish message or an extended Follow-up message has beenreceived during the last period of 2 TUs (Yes in step S502), the NANdevice 102 waits until the next DW period (step S503). If these messageshave been received during the last period of 2 TU, there is thepossibility that time could not secured sufficient for another NANdevice to transmit an extended Publish message or an extended Follow-upmessage and the message has not been transmitted. Accordingly, the NANdevice 102 waits until the next DW period since the NAN device 102 mayfurther receive an extended Publish message or an extended Follow-upmessage from another NAN device in the next DW period (step S503). Then,in the next DW period, the NAN device 102 again waits for receiving anextended Publish message or an extended Follow-up message until the DWperiod is complete (step S501).

If no extended Publish message or extended Follow-up message has beenreceived in the last period of 2 TU of the DW period (No in step S502),the procedure advances to step S504. In step S504, the NAN device 102determines whether or not extended Publish messages or extendedFollow-up messages have been received from at least eight NAN devices inthis DW period. This is because, if the NAN device 102 receives manypieces of NAN device information, there is the possibility that many NANdevices exist in the NAN cluster and the wireless band is congested, andthus there may be a NAN device that could not transmit any extendedPublish message or extended Follow-up message in the DW period.Accordingly, if at least eight extended Publish messages or extendedFollow-up messages have been received (Yes, in step S504), the NANdevice 102 waits for an extended Publish or extended Follow-up messagealso in the next DW period, as in the case of “Yes” in step S502 (stepS503).

If at least eight extended Publish messages or extended Follow-upmessages have not been received in step S504 (No in step S504), theprocedure advances to step S505. In step S505, the NAN device 102determines that it has sufficiently waited for receiving an extendedPublish message or extended Follow-up message, and decides to transmitNAN device information that has not yet been transmitted at a time as anextended Follow-up message at the start of the next DW period (stepS505).

With this flowchart, even if having received NAN device information froma single NAN device, the NAN device 102 does not immediately return theinformation to the NAN device 101. The NAN device 102 can determine thewaiting time depending on the timing at which the NAN device informationwas received and the number of times when the NAN device information wasreceived. Accordingly, it is possible to mitigate the band occupancythat may be caused due to a plurality of NAN devices in the NAN cluster107 transmitting NAN device information. Note that although, in stepS501, the NAN device 102 waits for reception during one DW period, thepresent invention is not limited to one DW period, and the NAN device102 may wait for reception during two or more DW periods. Furthermore,in FIG. 5, although, in step S502, it is determined whether or notapparatus information has been received during the last 2 TU of the DWperiod, the TU count is not limited to 2. Furthermore, although, in stepS504, it is determined whether or not at least eight pieces of NANdevice information have been received during the DW period, the numberof pieces of NAN device information is not limited to 8.

The description will return to FIG. 4. Here, the following descriptionwill be given assuming that the NAN device 102 receives, in the last 1TU of the DW period 420, the extended Publish message transmitted fromthe NAN device 104 in step S406. Since the situation corresponds to“Yes” in step S502, the NAN device 102 continues to wait for an extendedPublish message or extended Follow-up message also in a DW period 421,which is the next DW period. Accordingly, the NAN device 102 does nottransmit the NAN device information of the NAN device 103 and the NANdevice 104 to the NAN device 101. The following description will begiven further assuming that because the NAN device 103 and the NANdevice 104 take the role of Master, they need to forward the extendedSubscribe message received in step S404 but could not forward it in theDW period 420, since the DW period 420 is complete.

In DW period 421, in the DW period 420, the NAN device 103 and the NANdevice 104 each transmit an extended Subscribe message (steps S408 andS409). In the extended Subscribe messages that are transmitted in stepsS408 and S409, the same values are assigned to “Originator MAC Address”,“Collect ID”, and “Hop Count Limit” as those included in the extendedSubscribe messages transmitted in steps S402 and S404. On the otherhand, “Hop Count” is incremented to 2, since the extended Subscribemessages that are transmitted in steps S408 and 409 are forwardedmessages of the extended Subscribe message transmitted in step S404.Here, “Hop Count=Hop Count Limit=2”, and thus the NAN device (that is,the NAN device 102) that has received the extended Subscribe messagetransmitted in steps S408 and S409 and takes the role of Master does notforward this extended Subscribe message.

Upon receiving the extended Subscribe messages transmitted in steps S408and S409, the NAN device 102 determines, based on the Originator MACAddress and the Collect ID, that the messages are forwarded messages ofthe extended Subscribe message transmitted by the NAN device 102 in stepS404. Accordingly, the NAN device 102 does not respond to the receivedextended Subscribe messages. That is, the NAN device 102 does nottransmit any extended Publish message.

On the other hand, the NAN device 105 transmits, upon receiving theextended Subscribe message from the NAN device 103, an extended Publishmessage including its own NAN device information as a response (stepS410). Similarly, the NAN device 106 transmits, upon receiving theextended Subscribe from the NAN device 104, an extended Publish messageincluding its own NAN device information as a response (step S411). In“NAN device information” included in the extended Publish messagestransmitted in steps S410 and S411, the NAN device information of theNAN device 105 and the NAN device 106 are respectively included.Furthermore, 2 is assigned to “Hop Count”, that is, the same value asthat assigned to “Hop Count” of the extended Subscribe messagestransmitted in steps S408 and S409. Accordingly, the number of hops fromthe NAN device 101 is stored.

It is assumed that the transmission of the extended Publish messages insteps S410 and S411 is performed in the first 5 TUs of the DW period421. Accordingly, the NAN device 103 and the NAN device 104 respectivelydecide to transmit the NAN device information received in steps S410 andS411 as extended Follow-up messages to the NAN device 102 in the next DWperiod, that is, a DW period 422, in accordance with the flowchart ofFIG. 5 (No in step S502, and No in step S504).

Similarly, the NAN device 102 does not receive NAN device information inthe DW period 421. Accordingly, the NAN device 102 decides to transmitthe NAN device information received in steps S405 and S406 as anextended Follow-up message to the NAN device 101 in the next DW period,that is, the DW period 422, in accordance with the flowchart of FIG. 5(No in step S502, and No in step S504).

In the DW period 422, the NAN device 102 transmits, to the NAN device101, the NAN device information of the NAN device 103 and the NAN device104 as the extended Follow-up messages (step S412). The frame structureof an extended Follow-up message is shown in FIG. 8. Also, similarly,the NAN device 103 transmits the information of the NAN device 105 withan extended Follow-up message, and the NAN device 104 transmits theinformation of the NAN device 106 with an extended Follow-up message(steps S413 and S414).

FIG. 8 shows an extended Follow-up message configuration 800 accordingto the present embodiment for transmitting information of another NANdevice received with an extended Publish message to the originator. Inthe present embodiment, an extended Follow-up message is transmitted bythe NAN devices 102, 103, and 104 that have received the extendedPublish message. The message configuration 800 of FIG. 8 is obtained byextending a Follow-up message defined according to the NAN standard, andin “Service ID”, a value representing “Collect”, which indicates that itis a Follow-up relating to a service of requesting (that is, collecting)NAN device information, is stored. Furthermore, in “Service Info”,various types of information for transferring another piece of NANdevice information is stored. In “Originator MAC Address”, a MAC addressof an originator that has requested NAN device information is stored.That is, in the present embodiment, the MAC address of the NAN device101 is assigned to “Originator MAC Address”. To “Collect ID”, theCollect ID included in a received extended Publish message is assigned.Accordingly, the NAN device that has received the extended Follow-up canidentify to which NAN device information request the response is.

In “Number of NAN device information” that follows “Collect ID”, a valueindicating the number of other NAN devices included in this extendedFollow-up message is stored. 2 is stored in “Number of NAN deviceinformation” of the extended Follow-up message transmitted in step S412since the pieces of NAN device information of the NAN device 103 and theNAN device 104 are stored therein. On the other hand, 1 is stored in“Number of NAN device information” of the extended Follow-up messagetransmitted in step S413 since the NAN device information of the NANdevice 105 is stored therein. Similarly, 1 is stored in “Number of NANdevice information” of the extended Follow-up message that istransmitted in step S414 since the NAN device information of the NANdevice 106 is stored therein.

In “NAN device information” that follows “Number of NAN deviceinformation”, various types of NAN device information are stored.Various types of values in “NAN device information” are the same asthose in the extended Publish message described with reference to FIG.7, and thus descriptions thereof are omitted. Note however that, unlike“NAN device information” in the extended Publish message, “NAN deviceinformation” in the Follow-up message can include pieces of NAN deviceinformation of a plurality of other NAN devices. The number thereof isthe same as the value assigned to “Number of NAN device information”.The value of “NAN device information” in the extended Follow-up messagethat is transmitted in step S412 is 2, and is the same as the value of“NAN device information” in the extended Publish messages respectivelyreceived in steps S405 and S406. The value of “NAN device information”in the extended Follow-up message respectively transmitted in steps S413and S414 is 1, and is the same as the value of “NAN device information”in the extended Publish message respectively received in steps S410 andS411.

The description will return to FIG. 4. Upon receiving the extendedFollow-up messages in steps S413 and S414, the NAN device 102 determinesa timing of transmitting NAN device information again in accordance withthe flowchart of FIG. 5. Here, the following description will be givenassuming that the NAN device 102 has received the extended Follow-upmessages transmitted in steps S413 and S414 in the first 5 TUs of the DWperiod 422. At this time, the NAN device 102 devices to transmit thepieces of NAN device information of the NAN devices 105 and 106 as anextended Follow-up message in the next DW period in accordance with theflowchart of FIG. 5 (No in step S502, and No in step S504).

Then, in a DW period 423, the NAN device 102 transmits the extendedFollow-up message in “NAN device information” of which the pieces of NANdevice information of the NAN device 105 and the NAN device 106 to theNAN device 101 (step S415). With the above-described measure, the NANdevice 101 can collect information relating to another NAN device thatis participating in the NAN cluster 107.

In the present embodiment, instead of immediately forwarding a messageincluding NAN device information received in steps S405, S406, S413, andS414, the NAN device 102 transmits a plurality of pieces of NAN deviceinformation collectively at a time as in the processing in steps S412and S415. This reduces the radio band occupancy. Furthermore, in thepresent embodiment, a timing at which NAN device information of anotherNAN device is transmitted is determined depending on an extended Publishmessage or extended Follow-up message is received. Therefore, it ispossible to flexibly make a response depending on the number of neighborNAN devices or the wireless band. Note that, in the present embodiment,the pieces of NAN device information of all the NAN devices existing inthe NAN cluster 0107 are not transmitted collectively but aretransmitted three times in a divided manner in steps S403, S412, andS415. In other words, transmission of NAN device information to the NANdevice 101 is performed a plurality of times and thus the wireless bandis occupied, but it is advantageous that the NAN device 101 can rapidlyknow midway information.

Second Embodiment

The embodiment differs from the first embodiment in that the waitingtime for receiving NAN device information is determined based on “HopCount” and “Hop Count Limit”. The descriptions on the same features asin the first embodiment are omitted. In the present embodiment,processing performed by the waiting time determination unit 203 isdifferent from that of the first embodiment. FIG. 10 shows processingfor deciding the waiting time for receiving NAN device informationaccording to the present embodiment.

FIG. 10 shows a flowchart of the processing for determining the waitingtime for receiving NAN device information that is performed by the NANdevice 102 according to the present embodiment. The present processingcan be executed by the NAN device that has received an extendedSubscribe message. Note that the present processing may also be executedby another NAN device existing in the NAN cluster 107.

Upon receiving an extended Subscribe message, the NAN device 102 firstcalculates (Hop Count Limit−Hop Count−1)×2=N, based on “Hop Count Limit”(that is, frequency information relating to the number of times thatrequests for requesting NAN device information can be transmitted(relayed)) and “Hop Count” included in the received extended Subscribemessage. The NAN device 102 waits for an extended Publish message and anextended Follow-up message from another NAN device only during N-fold DWperiod, where N is the result of the calculation (step S1001).

The processing in step S1001 will be described. By calculating (HopCount Limit−Hop Count), it is possible to obtain the residual number ofhops for which the messages need to be transferred (the number of NANdevices via which the messages can be relayed). Here, a case isconsidered in which the next DW period is needed for the extendedSubscribe message transmitted in a DW period 920 to be forwarded, andyet another DW period is needed for a response to this extendedSubscribe message to be received. In this case, the number of DW periodneeded for the reception is determined, by doubling the residual numberof hops, which is obtained by (Hop Count Limit−Hop Count−1), taking intoconsideration the DW periods for the forwarding of the extendedSubscribe message and the reception of the response thereto. In a casewhere the values of “Hop Count Limit” and “Hop Count” are identical,both values have a negative value, but in this case, forwardingprocessing will not be executed anyway.

The NAN device 102 waits for receiving NAN device information inaccordance with the processing in step S1001, and determines whether ornot NAN device information of another NAN device (at least one of theNAN devices 103 to 106) could be received (step S1002). If NAN deviceinformation of another NAN device could be received (Yes in step S1002),the NAN device 102 transmits an extended Follow-up message with the NANdevice information of the other NAN device information included (stepS1003). On the other hand, if NAN device information of another NANdevice could not be received (No in step S1002), the NAN device 102 endsthe waiting for receiving the NAN device information of another NANdevice, and does not transmit the extended Follow-up message (stepS1004).

FIG. 9 shows a sequence diagram of an example of the flow of a series ofprocessing performed when the NAN device 101 acquires the NAN deviceinformation of the NAN devices 102 to 106 in the NAN cluster 107, in thepresent embodiment. Detailed descriptions of the same features as thoseof FIG. 4 are omitted.

The procedure from steps S901 to S903 is the same as in FIG. 4, and thusdetailed description thereof is omitted. Note however that the NANdevice 102 executes, upon receiving an extended Subscribe message instep S902, the flowchart of FIG. 10, and determines a waiting time foracquiring NAN device information. Here, the following description willbe given assuming that the extended Subscribe message received in stepS902 has Hop Count=0 and Hop Count Limit=2, as in the first embodiment.In this case, in step S1002, (Hop Count Limit−Hop Count−1)×2=2, andthus, during two DW periods, the NAN device 102 waits for NAN deviceinformation of another NAN device and does not perform forwardingprocessing. That is, the NAN device 102 waits for an extended Publishmessage and an extended Follow-up message from the DW period 920 inwhich the extended Subscribe message is transmitted in step S904 to thenext DW period, namely, a DW period 921 and a DW period 922.

The procedure from steps S905 to S908 is the same as in FIG. 4, and thusdetailed description thereof is omitted. Note however that the NANdevice 103 and the NAN device 104 execute, after having transmitted theextended Subscribe message, the flowchart of FIG. 10 to determine thewaiting time for receiving an extended Publish message and an extendedFollow-up message. Here, since Hop Count=1 and Hop Count Limit=2, theNAN device 103 and the NAN device 104 do not wait for information fromanother NAN device (0×DW period). In the case of “0 DW period”, the NANdevice 103 and the NAN device 104 are controlled to wait for an extendedPublish message and an extended Follow-up message only during thecurrent period, namely, the DW period 921, and transmit the received NANdevice information collectively in the next DW period 922 (step S1003).

The procedure from steps S909 and S910 is the same as in the firstembodiment, and thus detailed description thereof is omitted. In the DWperiod 922, the NAN device 103 and the NAN device 104 transmit anextended Follow-up message at the start of the DW period in accordancewith the flow of steps S1001, S1002, and S1003 of FIG. 10 (steps S911and S912). Note that the information stored in the extended Follow-upmessage is the same as that in the first embodiment.

In a DW period 923, the NAN device 102 transmits an extended Follow-upmessage at the start of the DW period in accordance with the flow ofsteps S1001, S1002, and S1003 (step S913). The extended Follow-upmessage includes all other pieces of NAN device information received bythe NAN device 102 before. Accordingly, the NAN device 102 transmits theextended Follow-up message with the NAN device information of the NANdevices 103, 104, 105, and 106 included in the messages received insteps S905, S906, S911, and S912 stored.

Thus, according to the present embodiment, as a result of the NAN device102 transmitting other received pieces of NAN device informationcollectively, it is possible to reduce the occupancy of the usedwireless band. In contrast to the first embodiment, the NAN device 102determines the waiting time for receiving NAN device information basedon “Hop Count” and “Hop Count Limit”. Accordingly, larger pieces of NANdevice information are likely to be transmitted at a time than in thefirst embodiment, and thus it is easy to prevent the band occupancy. Onthe other hand, in the Second embodiment, if a large value is assignedto “Hop Count Limit” but the NAN devices that corresponds to this numberof hops do not exist in the NAN cluster, it unnecessarily takes time toacquire NAN device information. In this view, in the first embodiment,the waiting time for receiving NAN device information is determinedirrespective of “Hop Count Limit”, and thus the NAN device that hasrequested NAN device information is likely to receive NAN deviceinformation more rapidly.

Modification

The first embodiment and the second embodiment may be combined with eachother. The second embodiment has the problem that if a large value isassigned to “Hop Count Limit”, it unnecessarily takes time to acquireinformation of another NAN device. Accordingly, if a certain value orgreater is assigned to “Hop Count Limit” or (Hop Count Limit−Hop Count),the NAN device 102 determines the waiting time in accordance with theflowchart of FIG. 4. On the other hand, if a value smaller than thecertain value is assigned to “Hop Count Limit” or (Hop Count Limit−HopCount), the NAN device 102 may be configured to determine the waitingtime in accordance with the flowchart of FIG. 10. This measure reducesthe likelihood that it unnecessarily takes time to acquire NAN deviceinformation if a large value is assigned to “Hop Count Limit”, and canmake it easy to put together a plurality of pieces of NAN deviceinformation if a small value is assigned to “Hop Count Limit”.

Furthermore, in FIGS. 5 and 10, the extended Follow-up message iscontrolled to be transmitted at the start of the next DW period, but thetiming at which an extended Follow-up message is transmitted is notlimited to this. For example, when an extended Follow-up message iscontrolled to be transmitted at the last of the DW period prior to thenext DW period, the NAN device that has requested NAN device informationcan collect NAN device information more rapidly.

Furthermore, in the foregoing embodiments, the NAN device may also becontrolled to be able to receive an extended Publish message or anextended Follow-up message not only in DW periods but also otherperiods. In this case, as a result of “Further NAN Service DiscoveryAttribute”, which is defined according to the NAN standard, beingincluded in an extended Subscribe message, the NAN device cancommunicate the period in which a frame can be transmitted and received,other than DW periods. The NAN device that has received it can transmitan extended Publish message or an extended Follow-up message in a periodother than the DW period that is designated with “Further NAN ServiceDiscovery Attribute”.

Furthermore, in the foregoing embodiments, a NAN device transmits, uponreceiving an extended Subscribe message, an extended Publish messagewith its NAN device information included therein, and then forwards anextended Subscribe message. In contrast, it is also possible that theNAN device first forwards an extended Subscribe message and thentransmits its NAN device information with an extended Publish message.Alternatively, it is also possible that, after a response to theforwarded extended Subscribe message is returned from another NANdevice, the NAN device transmits a response to the received extendedSubscribe message as an extended Follow-up message. That is, in theexample of FIG. 9, the NAN device 102 may add its own NAN deviceinformation to an extended Follow-up message in step S913, instead ofmaking a response in step S903. Furthermore, at this time, the NANdevice 102 can add NAN device information of the NAN devices 102 to 106to an extended Publish message, instead of an extended Follow-upmessage.

Furthermore, in FIGS. 7 and 8, “NAN device information” included in anextended Publish message and an extended Follow-up message is stored in“Service Info”. However, “NAN device information” may be included inanother field of the frame. “Service Info” can store data of up to 256bytes in the NAN standard, and thus if NAN device information has alarger size, the NAN device information needs to be transmitted using afield other than “Service Info”. For example, “Vendor SpecificAttribute”, which is a value freely assigned by each vender and iscompliance with the NAN standard, may be used. As a furthermodification, if NAN device information of 256 bytes or more in total isreceived from a plurality of NAN device, a NAN device may also transmitan extended Follow-up message within a range of 256 bytes at this time.

Furthermore, in the Second embodiment, in contrast to the firstembodiment, the NAN device waits for receiving information of anotherNAN device only in a fixed period, even if an extended Follow-up messageor Publish message is received at the last of the waiting time. However,for example, in the case that corresponds to steps S502 and S504, it isalso possible that the NAN device further waits for the next DW period.

According to the foregoing embodiments, thus, the NAN device canefficiently acquire NAN device information of another NAN deviceexisting in the NAN cluster in which it participates, realizing areduction in the radio band occupancy. Accordingly, it is possible for aNAN device to efficiently acquire NAN device information of a NAN devicethat does not exist in the coverage of radio waves of that NAN device,and to discover a service. Furthermore, even if a NAN device having alarge number of hops from the NAN device moves within the NAN cluster,it is highly possible that that NAN device can continuously discover aservice.

It is possible to reduce the radio band occupancy when informationrelating to another communication apparatus that exists in a cluster isacquired.

Other Embodiments

Embodiment(s) of the present invention can also be realized by acomputer of a system or apparatus that reads out and executes computerexecutable instructions (e.g., one or more programs) recorded on astorage medium (which may also be referred to more fully as a‘non-transitory computer-readable storage medium’) to perform thefunctions of one or more of the above-described embodiment(s) and/orthat includes one or more circuits (e.g., application specificintegrated circuit (ASIC)) for performing the functions of one or moreof the above-described embodiment(s), and by a method performed by thecomputer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s) and/or controlling the one or more circuits to perform thefunctions of one or more of the above-described embodiment(s). Thecomputer may comprise one or more processors (e.g., central processingunit (CPU), micro processing unit (MPU)) and may include a network ofseparate computers or separate processors to read out and execute thecomputer executable instructions. The computer executable instructionsmay be provided to the computer, for example, from a network or thestorage medium. The storage medium may include, for example, one or moreof a hard disk, a random-access memory (RAM), a read only memory (ROM),a storage of distributed computing systems, an optical disk (such as acompact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™),a flash memory device, a memory card, and the like.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

The invention claimed is:
 1. A communication apparatus comprising: oneor more processors; and one or more memories including instructionsthat, when executed by the one or more processors, cause the apparatusto: receive a first acquisition request, which is a request foracquiring apparatus information relating to another communicationapparatus that belongs to a NAN (Neighbor Awareness Networking) clusterto which a first other communication apparatus belongs and includesservice information indicating a predetermined service, from the firstother communication apparatus; transmit, in a case where the firstacquisition request is received, a second acquisition request thatcorresponds to the first acquisition request and includes the receivedservice information to the cluster; await reception of signals from aplurality of other communication apparatuses in response to thetransmitted second acquisition request, for a predetermined period; andtransmit, in a case of receiving the signals from each of at least asecond other communication apparatus and a third other communicationapparatus during the predetermined period, a signal which includes atleast apparatus information of the second other communicationapparatuses and apparatus information of the third other communicationapparatus that are included in the received signals.
 2. Thecommunication apparatus according to claim 1, wherein the instructionsfurther cause the apparatus to determine the predetermined period. 3.The communication apparatus according to claim 2, wherein theinstructions further cause the apparatus to determine the predeterminedperiod based on frequency information relating to the number of timesthat a request corresponding to the first acquisition request istransmitted.
 4. The communication apparatus according to claim 3,wherein the frequency information is included in the first acquisitionrequest.
 5. The communication apparatus according to claim 2, wherein,in a case where a signal is received from any one of the othercommunication apparatuses in a latter half of a Discovery Window periodof the cluster, the instructions further cause the apparatus todetermine, as the predetermined period, time that includes a nextDiscovery Window period of the Discovery Window period in which thesignal has been received.
 6. The communication apparatus according toclaim 1, wherein the instructions further cause the apparatus to receivethe first acquisition request during a Discovery Window period of thecluster.
 7. The communication apparatus according to claim 1, whereinthe instructions further cause the apparatus to transmit the secondacquisition request during a Discovery Window period of the cluster. 8.The communication apparatus according claim 1, wherein the instructionsfurther cause the apparatus to await, during a Discovery Window periodof the cluster, reception of signals from the other communicationapparatuses in response to the second acquisition request.
 9. Thecommunication apparatus according to claim 1, wherein the instructionsfurther cause the apparatus to transmit, during a Discovery Windowperiod of the cluster, the signal which includes at least apparatusinformation of the second other communication apparatuses and apparatusinformation of the third other communication apparatus that are includedin the received signals.
 10. The communication apparatus according toclaim 1, wherein the apparatus information includes information relatingto a service provided by the other communication apparatus.
 11. Thecommunication apparatus according to claim 1, wherein the apparatusinformation includes information relating to a role of the othercommunication apparatus in the cluster.
 12. The communication apparatusaccording to claim 1, wherein the predetermined service is a service forrequesting the apparatus information.
 13. The communication apparatusaccording to claim 1, wherein the service information is service IDindicating the predetermined service.
 14. A control method for acommunication apparatus, the method comprises: receiving a firstacquisition request, which is a request for acquiring apparatusinformation relating to another communication apparatus that belongs toa NAN (Neighbor Awareness Networking) cluster to which a first othercommunication apparatus belongs and includes service informationindicating a predetermined service, from the first other communicationapparatus; transmitting, in a case where the first acquisition requestis received, a second acquisition request that corresponds to the firstacquisition request and includes the received service information to thecluster; awaiting reception of signals from a plurality of othercommunication apparatuses in response to the transmitted secondacquisition request, for a predetermined period; and transmitting, in acase of receiving the signals from each of at least a second othercommunication apparatus and a third other communication apparatus duringthe predetermined period, a signal which includes at least apparatusinformation of the second other communication apparatuses and apparatusinformation of the third other communication apparatus that are includedin the received signals.
 15. A non-transitory computer-readable storagemedium storing a program for causing a computer to perform control of acommunication apparatus, the program causes the computer to: receive afirst acquisition request, which is a request for acquiring apparatusinformation relating to another communication apparatus that belongs toa NAN (Neighbor Awareness Networking) cluster to which a first othercommunication apparatus belongs and includes service informationindicating a predetermined service, from the first other communicationapparatus; transmit, in a case where the first acquisition request isreceived, a second acquisition request that corresponds to the firstacquisition request and includes the received service information to thecluster; await reception of signals from a plurality of othercommunication apparatuses in response to the transmitted secondacquisition request, for a predetermined period; and transmit, in a caseof receiving the signals from each of at least a second othercommunication apparatus and a third other communication apparatus duringthe predetermined period, a signal which includes at least apparatusinformation of the second other communication apparatuses and apparatusinformation of the third other communication apparatus that are includedin the received signals.